Business & Finance

Financially stressed United Airlines posted a net loss of $93 million for May, citing the "brutal challenge" of rising fuel costs. Had those costs remained the same as they were for the same month a year ago, United would have broken even, UAL Corp., its parent, said. The company is required under federal bankruptcy rules to submit a financial report each month. Despite the new torrent of red ink, a spokeswoman said the carrier still intends to emerge from bankruptcy in the fall.

Without identifying the interested party , the Chicago Board of Trade said it has been approached about a possible "business combination." Speculation immediately centered on the rival Chicago Mercantile Exchange, although the Chicago Tribune listed other possible suitors, among them the New York Mercantile Exchange and Germany's Eurex, the largest futures exchange in the world. The Board of Trade and the Chicago Mercantile Exchange previously have discussed merging, but nothing has come of those talks, the newspaper said. If they were to link up now, the combined company would surpass Eurex as No. 1. Less than a week ago, Chicago Board of Trade members OK'd plans for an initial public offering that's expected to be valued at about $2 billion.

In a deal valued at $1.05 billion, electric utility Calpine Corp. said it will sell all its remaining oil and natural gas assets to a subsidiary, Rosetta Resources Inc., effectively severing their relationship in the process. Last month, Calpine, of San Jose, Calif., announced plans to cut its debt load by as much as $3 billion this year.

Financial services giant Credit Suisse Group said it will drop the name First Boston from its investment banking division, effective next Jan. 1. The company said research "showed that it makes sense from the perspective of both our clients and our employees to move to a single brand." First Boston has existed as a trade name since the bank was founded in 1932. A partial stake was sold to Credit Suisse in 1978, and the latter acquired full control 10 years later. In making the move, Credit Suisse follows the lead of its Swiss rival, UBS, which eliminated the name of American subsidiary PaineWebber in late 2002.