TROY, Mich. (AP) — Shares of auto parts maker Delphi dropped slightly in their first day of trading after selling at $22 per share in an initial public stock offering on Thursday.

The former General Motors Co. division traded at $21.88, down 12 cents, or 0.6 percent, from the IPO price. The shares opened Thursday at $21.41, but rebounded by midmorning.

Delphi Automotive PLC, based in Troy, Mich., priced its shares in the IPO at the low end of the expected range of $22 to $24. The IPO raised $530 million, but the company won't get any of the proceeds because stockholders sold all 24.1 million shares in the offering. At the morning trading price, Delphi's market capitalization is about $5.27 billion.

Demand for the shares was light in the IPO, because Delphi isn't getting any of the proceeds and because of the poor performance of GM shares after its IPO last November, researcher Scott Sweet, owner of IPO Boutique, wrote in a note to investors.

"In my opinion, price sensitivity will be an issue," Sweet wrote.

GM's shares are down 32 percent from the IPO price of $33 on Nov. 18, 2010. They traded at $22.28 on Thursday morning.

Delphi's stock is trading on the New York Stock Exchange under the symbol "DLPH." Underwriters may buy 3.6 million more shares from stockholders at the IPO price if there's heavy demand from investors.

Delphi, which makes transmission controls, heating and air conditioning systems, safety components and electronics, was spun off from GM in 1999. High labor costs and GM production cuts sent the company into bankruptcy protection in 2005, but it emerged four years later after being bought by a group of investors.

Most of the Delphi shares belonged to well-known hedge fund manager John Paulson's Paulson & Co., which owned a 22 percent stake in the company. By selling about 20.6 million shares, Paulson & Co. will reduce its stake to about 15.8 percent. The rest of the shares in the offering were held by other investment firms.

The new version of Delphi is smaller and has billions less in debt. It is increasingly looking overseas for growth, particularly in China, the world's largest auto market. Detroit-based GM remains a major customer and accounted for 25 percent of Delphi's revenue last year.

In restructuring, Delphi cut thousands of jobs, slashed costs and sold off plants and businesses. The company no longer employs members of the United Auto Workers union. About 91 percent of its hourly workers are in low-cost countries.

Delphi also terminated its pension plans, transferring pension obligations for 70,000 Delphi workers and retirees to the federal government's Pension Benefit Guaranty Corp. The PBGC took responsibility for $6.1 billion in pension payments. The company no longer offers health insurance for retirees or employer-paid life insurance.

Delphi had been cleaning up its balance sheet ahead of the IPO. It bought back stakes owned by GM and the PBGC in March for $4.4 billion.

For the first nine months of this year, Delphi posted a profit of $911 million, up 49 percent from $612 million in the same period last year. Sales rose 19 percent to $12.1 billion from $10.2 billion.