Companies on both sides of the Atlantic have embarked on an early-year rush to issue debt in an effort to secure financing before any rise in borrowing costs.

The surge in bond issuance on Tuesday came amid optimism about the U.S. economy's growth prospects and corporate earnings. An estimated $35.6 billion in dollar-denominated bonds were priced on Tuesday, according to Dealogic.

In the U.S., General Electric's ( GE)finance arm led the issuance wave with the sale of $6 billion of debt. Europe's banks also raised more than €7 billion ($9 billion) in covered bonds -- that market's busiest day in more than a year.

On Monday, Warren Buffett's Berkshire Hathaway ( BRK.A) sold the first corporate debt of the year, with the $1.5 billion bond offering setting a positive tone for the dollar markets, the most important source of debt financing for companies and banks around the world.

On Tuesday, others including MetLife ( MET) and General Electric Capital, the group's financing arm, were planning deals.

January is typically a frenetic month for debt markets as investors look to put fresh funds to work and treasurers aim to secure some of their funding before entering the "blackout" period around corporate earnings.

However, this year the urge has only been made stronger by the economic outlook, which has fueled expectations that interest rates could rise.

"The incentives stack up for issuers to hit the debt market as hard and as quickly as they can," said Bill Cunningham, co-head of global active fixed income at State Street Global Advisers.

"There is a lot of debt to get done this year and there's an element of first-mover advantage right now," said Chris Tuffey, co-head of credit capital markets at Credit Suisse.

"We're seeing a good pipeline of deals building, but the strong volumes could belie the underlying market -- the European sovereign issue hasn't gone away and people are still worried about the economic outlook," he said.

This week has been also supercharged by a rush to complete deals ahead of Thursday's holiday across much of Europe.

"It's not the first time we've seen a rally in the first week. We need to see a few more days before really knowing how strong this is," said Frederic Zorzi, global co-head of the syndicate team at BNP Paribas.

The surge in bond issuance on Tuesday came as most equity markets rose to start the year on better growth prospects for the U.S. economy and corporate earnings.