New York, Jan 20 (DPA) US stocks posted strong gains Tuesday on the back of health and pharmaceutical companies that are hoping a special election in Massachusetts will derail major reforms of the health-insurance system.

The Dow Jones Industrial Average hit a 15-month high. An index of health companies climbed two percent as Massachusetts voters were at the polls Tuesday to replace the late senator Edward Kennedy.

A win for Republicans would cost Democrats the three-fifths super-majority in the Senate that they need to pass their version of health legislation. Debate over health-care policy has dominated Washington for the last year.

The reforms, which are touted as extending coverage to some 30 million US residents who have no health insurance, are opposed by health companies that will face more government restrictions on how they operate.

The election overshadowed US banking giant Citigroup's report of a $7.6-billion loss in the last three months of 2009, as it continues to feel the effects of the financial crisis while working to repay emergency government loans.

The loss came after three straight quarters of profits, though Citigroup Inc had posted a massive $17.3-billion loss in the final quarter of 2008. Citigroup's report dragged down other financials.

The Dow jumped 115.78 points, or 1.09 percent, closing at 10,725.43. The broader Standard & Poor's 500 Index surged 14.2 points, or 1.25 percent, to 1,150.23. The technology-heavy Nasdaq Composite Index added 32.41 points, or 1.42 percent, to 2,320.4.

The dollar gained against most major currencies, climbing against the euro to 69.99 euro cents from 69.52 euro cents Monday. The dollar climbed to 91.13 Japanese yen from 90.79 yen the previous day.