Capital injection raises Clydesdale's Tier 1 ratio by 1.4%
The capital increase will raise Clydesdale's Tier1 capital ratio by 1.4 per cent on a pro forma (limited requirement) basis.
Clydesdale Bank chief executive David Thorburn said: "This capital increase continues our focus on maintaining a conservative level of liquidity and strong capital ratios."
Last September Clydesdale was downgraded by credit rating agency Moody's amid doubts about its Australian parent company's commitment to its UK operations.
Moody's cut the long-term bank deposit and senior debt rating from A1 to A2 for both the Clydesdale Bank and Yorkshire Bank, both owned by NAB.
NAB rejected a s2 billion bid for its UK operations by private equity firm Sun Capital last year, saying it was too low.
NBNK Investments, a new banking venture set up by former Lloyds of London chairman Lord Levene, had also expressed an interest in buying the Clydesdale and Yorkshire banks.
However NBNK Investments withdrew from negotiations after failing to agree a price.