This week set a new record for the number of plus-sized stock offerings by public companies in the U.S.

A total of eight companies sold $1 billion or more apiece through follow-on offerings in the past five days, the highest number ever, according to data from Dealogic. The hefty follow-ons, in which corporations sell additional shares of their stock to the public, ranged from U.S. Bancorp's (USB) $2.5 billion offering on Monday to MGM Mirage Inc.'s (MGM) $1 billion offering on Wednesday.

Including non-billion-dollar deals, the last five days surpassed last week as the most active week in more than three years for the number of follow-on issuers. A total of 30 companies raised $15.4 billion, compared to 20 companies that raised $19.3 billion in the first week of May, and the highest number since 32 companies raised $10.1 billion during the week of Dec. 5, 2005, by Dealogic's reckoning.

Though the majority of the offerings came from financial services firms, some of which are seeking to pay back funds from the U.S. government's Troubled Asset Relief Program, other industries were represented, too. Besides MGM Mirage, Ford Motor Co. (F) raised $1.6 billion and Anadarko Petroleum Corp. (APC) raised $1.4 billion.

The stocks were sold into a market that wasn't as accommodating as it has been in recent weeks; every billion-plus deal declined after the sales. Bankers attributed the cooler reception to a bit of follow-on indigestion as well as broader market movements; the Standard & Poor's 500 Stock Index had sold off 4.6% from Monday through late in the trading day Friday. But they were still upbeat about what the large volume of stock sales indicates about investor attitudes.

"If the market can digest more than $30 billion in supply and only move down 4%, that's a very positive sign for the second half of 2009 and into 2010. It shows that buyers believe the market has truly turned," said Joe Castle, head of U.S. equities syndicate at Barclays Capital, which was a lead bookrunner on two of the deals.

Castle said as long as the market remains amenable, he expects a high level of issuance to continue in the follow-on market in the weeks ahead, albeit probably not as high as the past two weeks. Many of the largest raises from the financial services sector are probably behind the market now, but there will still be demand across all sectors to recapitalize balance sheets.

-By Lynn Cowan, Dow Jones Newswires; 301-270-0323; lynn.cowan@dowjones.com